JPH07263191A - Plasma processing device - Google Patents

Abstract

(57) [Summary] [Structure] In the plasma processing apparatus, the coil 3 capable of applying a multi-pole magnetic field and a high frequency voltage is provided at the outer peripheral portion of the processing chamber 1 or the outer peripheral portion of the discharge chamber. [Effect] Since the plasma loss on the wall surface is reduced, there is an effect that a higher density plasma can be generated and the plasma can be easily generated even in a lower pressure region.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma processing apparatus, and more particularly to a plasma processing apparatus suitable for etching and film-forming a sample such as a semiconductor element substrate using plasma.

[0002]

2. Description of the Related Art A conventional device is, for example, a Technical Proc.
eedings SEMICON / JAPAN 1993 P422 ~ P427 Introduction
of a new high density plasma reactor concept for
highaspect ratio oxide etching, J. Marks, K. Collin
As described in S., CLYang, D. Groechel, P. Kesuick, P. Arleo, a coil capable of applying a high frequency voltage was provided on the outer peripheral portion of the processing chamber.

[0003]

In the above-mentioned prior art, no consideration was given to the disappearance of plasma on the wall surface of the processing chamber. When a plasma is generated by providing a coil on the outer periphery of the processing chamber and applying a high frequency voltage to the coil,
Plasma is generated near the wall of the processing chamber. This is especially noticeable when a helical coil is used. On the other hand, on the wall surface of the processing chamber, the plasma comes into contact with the wall surface, and as a result, the plasma disappears. Therefore, there is a problem that it is difficult to generate high-density plasma as a whole and it is difficult to generate plasma under low pressure conditions.

It is an object of the present invention to provide a plasma processing apparatus which can generate higher density plasma and can easily generate plasma even under a low pressure condition.

[0005]

To achieve the above object, a coil capable of applying a multi-pole magnetic field and a high frequency voltage is provided at the outer peripheral portion of the processing chamber or the outer peripheral portion of the discharge chamber.

[0006]

By applying a high frequency voltage to the coil provided on the outer peripheral portion of the processing chamber or the outer peripheral portion of the discharge chamber, plasma with higher density is generated near the wall surface. On the other hand, by providing the multi-pole magnetic field near the coil, the generated plasma has a reduced portion in contact with the wall surface, and as a result, the disappearance of the plasma on the wall surface is reduced, so that the plasma density is increased as a whole. In addition, plasma can be easily generated even in a low pressure region because of the reduction of plasma loss on the wall surface and the binding of electrons (which becomes a plasma ignition source) by the multipolar magnetic field.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. FIG. 1 is a vertical cross-sectional view of an etching processing apparatus which is an embodiment of the plasma processing apparatus of the present invention. After decompressing the inside of the processing chamber 1 partitioned by the container 1a and the quartz container 2 by a vacuum exhaust device (not shown), an etching gas is introduced into the processing chamber 1 by a gas supply device (not shown), Adjust to pressure. A coil 3 and a multi-pole magnetic field are provided on the outer periphery of a container made of a dielectric material such as quartz or alumina ceramics, in the present embodiment, a quartz container 2. In the case of the present embodiment, the coil 3 is a helical coil, and the multipole magnetic field is generated by arranging the N poles and S poles of the permanent magnets 4 alternately in a ring shape. Further, the coil 3 is arranged between the permanent magnets 4. The coil 3 is connected to a high frequency power source 5 via a matching unit (not shown) and is supplied with a high frequency voltage. As the high frequency power source 5, for example, a frequency of 2M
A high frequency power source such as Hz or 13.56 MHz may be used. Otherwise, a high frequency power source in the frequency range of about 500 M to about 100 kHz can be used.

By supplying a high frequency voltage to the coil 3 provided on the outer peripheral portion of the processing chamber 1, high density plasma is generated near the wall surface of the processing chamber 1. On the other hand, by providing the multi-pole magnetic field near the coil 3, the generated plasma reduces the portion connected to the wall surface of the processing chamber 1, and as a result, the disappearance of the plasma on the wall surface is reduced. Will increase. Further, since the plasma loss on the wall surface is reduced and the electrons serving as the ignition source of the plasma are bundled by the multipolar magnetic field, it is possible to easily generate the plasma even in the low pressure region. The material 7 to be processed placed on the sample table 6 is etched by the plasma thus generated. Further, in order to control the etching shape of the material 7 to be processed, a high frequency power source 8 is connected to the sample stage 6 via a matching device (not shown) and a high frequency voltage is applied.

According to the first embodiment of the present invention, since the multi-pole magnetic field and the coil 3 are provided on the outer peripheral portion of the processing chamber 1, the plasma loss on the wall surface of the processing chamber 1 is reduced, so that the higher magnetic field can be obtained. There is an effect that plasma of high density can be generated and that plasma can be easily generated even in a lower pressure region.

A second embodiment of the present invention will be described with reference to FIG. This embodiment is a combination of the plasma generation method described in the first embodiment and the plasma generation method by magnetic field microwave discharge. The microwave of 2.45 GHz oscillated from the magnetron 9 in this case is the waveguide 10.
It propagates through the inside, passes through the quartz window 11, and enters the discharge tube 1b. The discharge tube 1b is in the magnetic field region generated by the coil 12. Electron cyclotron resonance (hereinafter referred to as ECR
The plasma generated in the discharge tube 1b is guided by the divergent magnetic field into the quartz container 2b, which is the processing chamber 1, but the plasma density distribution is larger in the central portion than in the outer peripheral portion. In the case of this embodiment, the coil 3 is provided on the outer peripheral portion of the quartz container 2b. By this coil 3, by generating plasma also on the side wall which is the outer periphery of the processing chamber 1 or by additionally heating the plasma,
It is possible to obtain a more uniform plasma distribution as a whole in the processing chamber 1. According to this embodiment, there is an effect that more uniform plasma can be generated.

A third embodiment of the present invention will be described with reference to FIGS. This embodiment is a combination of the magnetic field microwave discharge using a slot antenna and the plasma generation method shown in the first embodiment. Magnetron 9
The microwave oscillated from propagates in the waveguide 10 and is introduced into the cylindrical circular TE ₀₁ resonator 13. Resonator 13
A plurality of slot antennas 14 are provided on the bottom surface of the slot antenna 14 radially outward from the center as shown in FIG. In addition, a space is provided between the slot antenna 14 and the quartz window 11, and the microwave radiated from the slot antenna 14 propagates through the above-mentioned space and then, as a whole, a circular TE ₀₁ mode microwave is generated. It is formed, passes through the quartz window 11, enters the discharge tube 1b, and plasma is generated.

The plasma is guided into the quartz container 2b which is the processing chamber 1 by the divergent magnetic field as in the case of the second embodiment. In the case of the present embodiment, the plasma is coiled around the lower portion of the processing chamber 1. A coil 15 generates a magnetic field in the opposite direction to the magnetic field generated by 12. According to the present embodiment, as in the second embodiment, plasma uniformity can be improved as a whole by the plasma generation on the side wall of the processing chamber 1 by the coil 3, but by the coil 15 for generating the reverse magnetic field, Controlling the magnetic lines of force of the magnetic field generated in the processing chamber 1 also has the effect of improving the plasma uniformity.

A fourth embodiment of the present invention will be described with reference to FIG. In this embodiment, the permanent magnet 4 is provided on the outer circumference of the coil 3 in the third embodiment. According to the present embodiment, in addition to the effect similar to that of the third embodiment, the coils 3 can be provided more densely, so that it is easier to generate plasma even in the low pressure region.

A fifth embodiment of the present invention will be described with reference to FIG. In this embodiment, the coils 12 and 15 for generating the axial magnetic field in the third embodiment are removed. According to the present embodiment, in addition to the effects of the third embodiment, there is an effect that a uniform plasma is more easily generated because there is no axial magnetic field. Further, in the case of the present embodiment, the permanent magnet 4 may be further removed and plasma may be generated in the state of no magnetic field. In that case, an effect that a more uniform plasma is easily generated is added.

A sixth embodiment of the present invention will be described with reference to FIG. In this embodiment, the diffusion region in the third embodiment is eliminated and the coil 3 is provided on the outer peripheral portion of the discharge region.
Since the coil 3 generates plasma with high density near the inner wall surface of the quartz container 2b, there is an effect that uniform plasma can be easily generated as a whole.

A seventh embodiment of the present invention will be described with reference to FIG. The present embodiment is a combination of the helicon wave discharge and the plasma generation method shown in the first embodiment of the present invention. The antenna 1 for helicon wave excitation is provided on the outer circumference of the quartz discharge tube 16 placed in the magnetic field region generated by the coil 12.
7, a high frequency power source 18 is connected to the antenna 17 via a matching device (not shown), and plasma is generated by helicon wave discharge. According to this embodiment, as in the third embodiment, there is an effect that more uniform plasma can be generated.

An eighth embodiment of the present invention will be described with reference to FIG. In this embodiment, transfer coupled plasma discharge (hereinafter, abbreviated as TCP discharge) TCP discharge is combined with the plasma generation method shown in the first embodiment of the present invention. A high frequency power supply 18 is provided through a matching device (not shown) on a spiral coil 20 provided on the quartz plate 19.
, And plasma is generated by TCP discharge. According to the present embodiment, as in the third embodiment, it is possible to generate more uniform plasma.

A ninth embodiment of the present invention will be described with reference to FIG. In this example, a volume coupled plasma discharge (hereinafter,
CCP discharge) CCP discharge is a combination of so-called parallel plate type discharge and the plasma generation method shown in the first embodiment of the present invention. Matching device (not shown)
The grounded electrode 21 is provided so as to face the sample stage 6 connected to the high frequency power source 8 via the CCP discharge. According to this embodiment, as in the third embodiment, there is an effect that more uniform plasma can be generated.

A tenth embodiment of the present invention will be described with reference to FIG. In the present embodiment, the magnetron discharge is combined with the plasma generation method shown in the first embodiment of the present invention. The permanent magnet 22 is arranged on the electrode 21 provided so as to face the sample stage 6 to which the high frequency power source 8 is connected via a matching unit (not shown), and magnetron discharge is performed. According to this embodiment, as in the third embodiment, there is an effect that more uniform plasma can be generated.

Further, although the dry etching apparatus has been described in each of the above-mentioned embodiments, the same operation and effect can be obtained also in the plasma processing apparatus such as the plasma CVD apparatus and the ashing apparatus.

[0021]

According to the present invention, since the coil capable of applying the multi-pole magnetic field and the high frequency voltage is provided in the outer peripheral portion of the processing chamber or the outer peripheral portion of the discharge chamber, the plasma loss on the wall surface is reduced, There is an effect that high-density plasma can be generated and plasma can be easily generated even in a lower pressure region.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a processing chamber portion of an etching processing apparatus according to a first embodiment of the present invention.

FIG. 2 is a vertical sectional view of a processing chamber portion of an etching processing apparatus according to a second embodiment of the present invention.

FIG. 3 is a vertical sectional view of a processing chamber portion of an etching processing apparatus according to a third embodiment of the present invention.

4 is a view of the slot antenna in FIG. 3 viewed from above.

FIG. 5 is a vertical sectional view of a processing chamber portion of an etching processing apparatus according to a fourth embodiment of the present invention.

FIG. 6 is a vertical sectional view of a processing chamber portion of an etching processing apparatus according to a fifth embodiment of the present invention.

FIG. 7 is a vertical sectional view of a processing chamber portion of an etching processing apparatus according to a sixth embodiment of the present invention.

FIG. 8 is a vertical sectional view of a processing chamber portion of an etching processing apparatus according to a seventh embodiment of the present invention.

FIG. 9 is a vertical sectional view of a processing chamber portion of an etching processing apparatus according to an eighth embodiment of the present invention.

FIG. 10 is a vertical sectional view of a processing chamber portion of an etching processing apparatus according to a ninth embodiment of the present invention.

FIG. 11 is a vertical sectional view of a processing chamber portion of an etching processing apparatus according to a tenth embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Processing chamber, 1a ... Container, 1b ... Discharge tube, 22b ... Quartz container, 3 ... Coil, 4 ... Permanent magnet, 5 ... High frequency power supply, 6 ... Sample stage, 7 ... Processed material, 8 ... High frequency Power, 9 ...
Magnetron, 10, 10b ... Waveguide, 11 ... Quartz window,
12 ... Coil, 13 ... Resonator, 14 ... Slot antenna, 15 ... Coil, 16 ... Quartz discharge tube, 17 ... Antenna, 18 ... High frequency power source, 19 ... Quartz plate, 20 ... Coil,
21 ... Electrodes, 22 ... Permanent magnets.

Continuation of front page (51) Int.Cl. ⁶ Identification code Office reference number FI Technical display area H01L 21/3065 21/31

Claims (6)

[Claims] 1. A plasma processing apparatus comprising a plasma generator, a processing chamber capable of decompressing, a gas supply apparatus, and a vacuum exhaust apparatus, wherein a coil capable of applying a multipolar magnetic field and a high frequency voltage is provided.
A plasma processing apparatus provided on the outer peripheral portion of the processing chamber or the outer peripheral portion of the discharge chamber. 2. The plasma processing apparatus according to claim 1, wherein the multi-pole magnetic field is generated by alternately arranging S poles and N poles of permanent magnets. 3. The plasma processing apparatus according to claim 1, wherein the coil is a helical coil. 4. The plasma processing apparatus according to claim 1, wherein a helical coil is provided between the permanent magnets provided to generate the multipolar magnetic field. 5. In addition to a microwave plasma generator, a helicon wave plasma discharge generator, a transfer coupled plasma discharge generator, or a capacitively coupled plasma discharge generator, the multipole magnetic field and the high frequency voltage can be applied. The plasma processing apparatus according to claim 1, wherein the coil is provided on an outer peripheral portion of the processing chamber or an outer peripheral portion of the discharge chamber. 6. In addition to a microwave plasma generator, a helicon wave plasma discharge generator, or a transfer coupled plasma discharge generator, a coil to which the high frequency voltage can be applied is provided at the outer peripheral portion of the processing chamber or the outer peripheral portion of the discharge chamber. The plasma processing apparatus according to claim 1, wherein: